Flat Earth Debunking Bullets

[George]

Last week a poll (taken in Feb.) revealed a surprising lack of knowledge by younger adults about the shape of the Earth -- flat vs. round (spherical).

Only 66% of those in the age range of 18 to 24 consider the Earth round, with and additional 7% of them unsure; 94% for those 55 and older, with 2% unsure.

Here are the results of the poll.

Given the roots (1 of 2) to this forum (ie Bad Astronomy), I would like to do a Bullet listing of the lines of evidence against the Flat Earth hypothesis that has, well, fallen flat and with a big thud.

Since I couldn't find another thread like this, I will attempt to amend this OP to produce the bullet list, though I know there are time limits on edits. If editing is a problem, I will do a new thread to show a summary of this one.

Also, it might be fun to speculate on why the younger crowd seems confused on this topic. I was watching Gutfeld's show, when he raised this topic. He is convinced the Earth is not flat because of all the garbage we still have since we have no edge to throw it off.

Arguments against a Flat Earth:
1) Images from space and from near space.
2) No edge found.
3) Traveling along any latitude will return you to the same place, though this trip is expensive.
4) Traveling a great circle route is faster and shorter.
5) Coriolis effect
6) Gravity will cause a sphere to form.
7) All other planets are round, including the smaller dwarf planets.
8) Ship's masts are seen first at the horizon. Clouds are lower on the horizon than expected.
9) Cloud tops during sunset will go into the shadow of other, more distant, clouds sooner than expected.
[B]10) The fact that you see farther from heights, either skyscrapers or mountains.
11) The shape of the Earth's shadow on the Moon during an ecilpse
12) Time zones and differences in sunrise / sunset times within a time zone and from zone-to-zone
13) Changes in visible stars and constellations with changes in latitude (can't see the Southern Cross from the Northern Hemisphere, for example)
14) Changes in day length with latitude
16a) The curvature of the Earth has to be accounted for in the design of long suspension bridges (link)
16b) Sewer lines and concrete slabs using lasers to set grade will puddle in the middle unless adjusted for curvature.
17) The Foucault pendulum
18) Gravity would work very differently on a finite flat plane than a sphere (link)
19) Flat Earth models would not seem to give explanations of seasons (particularly difference between Northern and Southern hemisphere), colder conditions at the North and South poles, atmospheric or ocean circulation
20) Earth curvature affects weather radar (NWS)
21) Distant views of the Earth from space never show an edge-on view.
22) A clear sky is always blue regardless of location.
23) The Sun appears yellow during when on the horizon regardless of location.

Humorous pseudo-objective evidence:
1a) Garbage is pilling-up implying no edge in which to push it off.
1b) Cats would have pushed off enough to be noticeable.

Arguments favoring a Flat Earth:
1) It looks flat when standing on the ground.
2) Inferring flatness from one or more religious texts.

[profloater]

Last week a poll (taken in Feb.) revealed a surprising lack of knowledge by younger adults about the shape of the Earth -- flat vs. round (spherical).

Only 66% of those in the age range of 18 to 24 consider the Earth round, with and additional 7% of them unsure; 94% for those 55 and older, with 2% unsure.

Here are the results of the poll.

Given the roots (1 of 2) to this forum (ie Bad Astronomy), I would like to do a Bullet listing of the lines of evidence against the Flat Earth hypothesis that has, well, fallen flat and with a big thud.

Since I couldn't find another thread like this, I will attempt to amend this OP to produce the bullet list, though I know there are time limits on edits. If editing is a problem, I will do a new thread to show a summary of this one.

Also, it might be fun to speculate on why the younger crowd seems confused on this topic. I was watching Gutfeld's show, when he raised this topic. He is convinced the Earth is not flat because of all the garbage we still have since we have no edge to throw it off.

Arguments against a Flat Earth:

1) Images from space.
2) No edge found.
3) Traveling along any latitude will return you to the same place, though this trip is expensive.
4) Traveling a great circle route is faster and shorter.
5) Coriolis effect
6) Gravity will cause a sphere to form.
7) All other planets are round, including the smaller dwarf planets.
8) Ship's masts are seen first at the horizon. Clouds are lower on the horizon than expected.
9) Cloud tops during sunset will go into the shadow of other, more distant, clouds sooner than expected.


Arguments favoring a Flat Earth:
1) It looks flat when standing on the ground.

I suppose this is strong evidence for widespread scepticism about what we are told. Even in airplane travel the circular horizon could be just a convex disc. Same for ships approaching. If some people do not believe images from space for example, because they have not seen it for themselves, then intergenerational trust is way below what it used to be. I guess this is more worrying than similar polls that demonstrate widespread ignorance of history, current affairs, healthy eating and STDs. Is it possible loads of young people choose not to believe anything the old regime says?

[George]

Is it possible loads of young people choose not to believe anything the old regime says?

I think that is partially true and it's the one thing they would believe coming from old-regime me.

There seems to be a lot of emphasis (too much so) on the standardized tests and less on helping students really see what is happening. I wonder how much the increase in social media has made them choose to experience life from a little hand screen and in lieu of learning from doing. If the importance of experiments is unrealized, then so too the scientific method and the world becomes, well, more flat.

[antoniseb]

I don't believe the poll. I DO believe that there is an effort to make anti-science claims, and a large group of people who are amused to publicly agree with them, but who, if presented with a life-and-death (or even a real money) situation in which they had to get this right would state that the Earth was (close to) spherical.

[profloater]

Ok a different question: at what age does a child respond with evidence if you ask "how do you know the world is (close to) a sphere?
I cannot ever remember questioning the received wisdom, there was a globe in the main room as long as i can remember. I never thought to question if it was a hoax.

[schlaugh]

I’d also look at the polling methodology and question formulation. You might get a different result to “The world is round: true or false” vs “I have always believed the world is round. “

And I would not put it past younger folk to try to spoof the poll takers.


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[Swift]

1B) You don't have to go all the way to space or have a rocket to see the curvature (images from students using a helium balloon at 30 km)

10) The fact that you see further from heights, either skyscrapers or mountains.
11) The shape of the Earth's shadow on the Moon during an ecilpse
12) Time zones and differences in sunrise / sunset times within a time zone and from zone-to-zone
13) Changes in visible stars and constellations with changes in latitude (can't see the Southern Cross from the Northern Hemisphere, for example)
14) Changes in day length with latitude
15) And then of course there are cats....

[George]

I don't believe the poll. I DO believe that there is an effort to make anti-science claims, and a large group of people who are amused to publicly agree with them, but who, if presented with a life-and-death (or even a real money) situation in which they had to get this right would state that the Earth was (close to) spherical.

Yes, perhaps there is a lack of seriousness on the part of those polled and we don't know if the those surveyed represented a fair sampling. That there were over 8,200 polled however is somewhat significant so could we not say that the margin of error isn't too large to expect?

[George]

I’d also look at the polling methodology and question formulation. You might get a different result to “The world is round: true or false” vs “I have always believed the world is round. “

And I would not put it past younger folk to try to spoof the poll takers.

Yep, there's that. I recall an anti-establishment Clown Party winning against the incumbent party at a major university back when I was in college. The armadillo was to be the new mascot, IIRC. [Being a rival college, during halftime at the football game we (not me) released armadillos on the 50 yard line. They can run fast when they are chased. ]

[tony873004]

Here is a Youtube I made with my drone. From a height of about 30 feet, it shows the Sun setting on the ocean horizon. I then quickly ascend to 100 feet. This causes the Sun to rise.
https://youtu.be/ZIZgDEwZS-c?t=249

[KaiYeves]

Yep, there's that. I recall an anti-establishment Clown Party winning against the incumbent party at a major university back when I was in college. The armadillo was to be the new mascot, IIRC. [Being a rival college, during halftime at the football game we (not me) released armadillos on the 50 yard line. They can run fast when they are chased. ]

Indeed, I think the vast majority of people asserting the "Flat Earth" theory in general online are to some extent joking and/or trying to provoke emotional reactions.

(As I was bullied in Middle School by other students who found it funny that I had strong emotional reactions to some minor-seeming things because [unbeknownst to both them and myself at the time] I have Asperger's Syndrome, I thoroughly disapprove of the practice of annoying people in order to be entertained by watching them get upset.)

[Swift]

16) The curvature of the Earth has to be accounted for in the design of long suspension bridges (link)
17) The Foucault pendulum
18) Gravity would work very differently on a finite flat plane than a sphere (link)
19) Flat Earth models would not seem to give explanations of seasons (particularly difference between Northern and Southern hemisphere), colder conditions at the North and South poles, atmospheric or ocean circulation
20) Earth curvature affects weather radar (NWS)

[DaveC426913]

16) The curvature of the Earth has to be accounted for in the design of long suspension bridges (link)

This alone should be enough. If the "test" for sphericity could be reduced to something on a human reproducible scale (such as two plumb bobs a thousand feet apart), one would think that would clinch it.

[George]

16) The curvature of the Earth has to be accounted for in the design of long suspension bridges (link)

Yes, and I added a 16b to mention two other construction items that are problematic when grades are set using lasers. I was in sales when lasers were first introduced and sold the first lasers to utility contractors who never had to worry about curvature using their batter-boards (taken from engineering hubs already adjusted for curvature).

[George]

I added 3 more:
21) Distant views of the Earth from space never show an edge-on view.
22) A clear sky is always blue regardless of location.
23) The Sun appears yellow when on the horizon regardless of location.

The reason the sky is blue is due to a set amount of atmosphere that causes just the right amount of scattering. The color would change if the amount of atmosphere changes. This is true for the Sun's color, and the area around it, for the same reason (scattering).

[profloater]

I added 3 more:
21) Distant views of the Earth from space never show an edge-on view.
22) A clear sky is always blue regardless of location.
23) The Sun appears yellow when on the horizon regardless of location.

The reason the sky is blue is due to a set amount of atmosphere that causes just the right amount of scattering. The color would change if the amount of atmosphere changes. This is true for the Sun's color, and the area around it, for the same reason (scattering).

Playing devil's advocate, a cynic has already ignored all pictures having seen jurassic park, cgi and colours require some kind of model. If i got myself a boat and sailed how would i trust my compass not to just sail in a circle. . .? Basically you have to trust other people. If that breaks then everybody is lying. I'm only sure about australia because i trust people, otherwise it could be atlantis.

[grapes]

Indeed, I think the vast majority of people asserting the "Flat Earth" theory in general online are to some extent joking and/or trying to provoke emotional reactions.

New poll results: 80% of respondents enjoy jerking your chain

[George]

New poll results: 80% of respondents enjoy jerking your chain

Yep, that's at least half right.

[molesworth]

A couple of additional thoughts :

24) Measuring the height of the sun, pole star etc. using simple techniques, a la Eratosthenese, gives inconsistent results. The measured values only make sense on a spherical Earth.
25) Distances measured when travelling along lines of latitude are incorrect as you move away from the equator, becoming nonsensically wrong as you move to e.g. South Africa, Australia or New Zealand.
26) It's relatively easy to build your own weather satellite receiver using a £20 / $20 dongle, some wire, and free software. You can check that the cloud images match your (or friends', relatives' etc.) location.

[profloater]

A couple of additional thoughts :

24) Measuring the height of the sun, pole star etc. using simple techniques, a la Eratosthenese, gives inconsistent results. The measured values only make sense on a spherical Earth.
25) Distances measured when travelling along lines of latitude are incorrect as you move away from the equator, becoming nonsensically wrong as you move to e.g. South Africa, Australia or New Zealand.
26) It's relatively easy to build your own weather satellite receiver using a £20 / $20 dongle, some wire, and free software. You can check that the cloud images match your (or friends', relatives' etc.) location.

any fule kno that sensible people do not use pics of clouds to check there frends locashun. They ask there mum and thats that.

[Solfe]

Arguments favoring a Flat Earth:
1) It looks flat when standing on the ground.
2) Inferring flatness from one or more religious texts.

There is a book at UB where the author was standing in a depression in Florida. He surmised the earth is a sphere, but we are inside of it. It'd be amusing to set him against a flat earther.

More trivia: The book was vaguely mention in Ghostbusters. All of the books from the film are real (as in they exist, not that they are true) and available at UB's Lockwood library.

[molesworth]

any fule kno that sensible people do not use pics of clouds to check there frends locashun. They ask there mum and thats that.

I had not thort of that, chiz! :-D

However, to add to the list :

27) Watch a video from space and hold up a big sign saying "Hello Mum!" to prove that the satellites are up there - UK satellite makes HD colour movies of Earth!

[profloater]

I had not thort of that, chiz! :-D

However, to add to the list :

27) Watch a video from space and hold up a big sign saying "Hello Mum!" to prove that the satellites are up there - UK satellite makes HD colour movies of Earth!

I hav seen a flick where they read newspaper from space so yu only hav to read an Aussie paper from yur fone, right? an if its upside down, that proovs it, right? job dun.

[George]

A couple of additional thoughts :

24) Measuring the height of the sun, pole star etc. using simple techniques, a la Eratosthenese, gives inconsistent results. The measured values only make sense on a spherical Earth.

Please explain this further.

25) Distances measured when travelling along lines of latitude are incorrect as you move away from the equator, becoming nonsensically wrong as you move to e.g. South Africa, Australia or New Zealand.

I think #13 covers this.

26) It's relatively easy to build your own weather satellite receiver using a £20 / $20 dongle, some wire, and free software. You can check that the cloud images match your (or friends', relatives' etc.) location.

Please explain this one as well.

[George]

There is a book at UB where the author was standing in a depression in Florida. He surmised the earth is a sphere, but we are inside of it. It'd be amusing to set him against a flat earther.

More trivia: The book was vaguely mention in Ghostbusters. All of the books from the film are real (as in they exist, not that they are true) and available at UB's Lockwood library.

I suppose that there is an important distinction between these two imaginations: fertile and fertilizer.

[KaiYeves]

25) Distances measured when travelling along lines of latitude are incorrect as you move away from the equator, becoming nonsensically wrong as you move to e.g. South Africa, Australia or New Zealand.

Here’s a good analysis post about this from the International Skeptics Forum that uses sailing circumnavigation and does the math.

(Also relevant to my other interests, but that’s beside the point...)

[profloater]

I was just hearing about the Victoria, one of Magellan's ships, that completed a round the world trip, very possibly the first ever and the first to be recorded. Even though they could not work out longitude despite trying, they did find the spice islands they knew were in the East by setting off Westwards and rounding Cape Horn, discovering the Pacific and Scurvy in that order. They, or he at least, did seem to have a global concept. Do flat Earthers believe it was a hoax perpetuated by every round the world sailor since?

[molesworth]

A couple of additional thoughts :

24) Measuring the height of the sun, pole star etc. using simple techniques, a la Eratosthenese, gives inconsistent results. The measured values only make sense on a spherical Earth.

Please explain this further.

Happy to help...

I've seen claims from flat-earthers that Eratosthenes' measurement of the Earth's radius could also be interpreted as the Sun being about 3,000 miles (if I recall right) above a flat Earth. His measurements were taken from Syene (now Aswad) and Alexandria, and he calculated a radius which, depending on which value you take for the ancient measure of a "stade" which was within 10% to 15% of today's value.

The flat Earth proponents, quite validly, show that using basic geometry this single measurement could be interpreted as the Sun at a height of 3,000 miles. However, if you use the same method to take measurements from other locations, the "height" values calculated for the Sun are different for each location. Either there is something seriously wrong with geometry (in which case all bets about the entire universe are off) or there is something wrong with the flat Earth model. However, an alternate model, based on a spherical Earth and the Sun being a very long distance away, fits the measurements very well, and so must be a better interpretation of the data.

25) Distances measured when travelling along lines of latitude are incorrect as you move away from the equator, becoming nonsensically wrong as you move to e.g. South Africa, Australia or New Zealand.

I think #13 covers this.

Not quite. #13 is about the changes in the stars visible with latitude, and changes in the angles of stars above the horizon. What I'm meaning is the distance measured on the ground between locations which are on the same latitude, i.e. due east or west of each other. For example, Philadelphia and Denver, Edinburgh and Moscow or Cape Town and Sydney. On a spherical Earth, each degree of longitude at the equator is 60 nautical miles. As you move north or south, the measured length along one degree becomes smaller, eventually becoming zero at the poles.

However, on a flat Earth, the measured distance per degree does reduce as you move north (although not in the same way as on a sphere, which shows something is not quite right), but the distance per degree increases as you move south, with hilarious results. For instance, the distance between Perth (Oz) and Sydney, although not quite exactly on the same latitude, is around 1,770 nautical miles (2,038 statute miles, 3,280 Km). On a flat Earth map, the distance between them is about 2,440 nautical miles (2,810 miles, 4,520 Km) - if my rough calculations are correct. This is a very large, and very noticeable error, especially if you're planning to travel between southerly locations!

26) It's relatively easy to build your own weather satellite receiver using a £20 / $20 dongle, some wire, and free software. You can check that the cloud images match your (or friends', relatives' etc.) location.

Please explain this one as well.

I'm actually building one myself, having bought the dongle a couple of weeks ago :-) The main component is a software defined radio (SDR) module, such as this one I bought from Amazon UK, but similar others are available. There's a good site with information on setting up the software, e.g. here and here.

I'm still getting to grips with it, and it seems that I need a better antenna to pick up satellite signals, but I've successfully set it up as an aircraft ADSB receiver, which is quite fun. I'll hopefully get it working in the next couple of months, and I've found a couple of good antenna designs which should work.

[molesworth]

Here’s a good analysis post about this from the International Skeptics Forum that uses sailing circumnavigation and does the math.

(Also relevant to my other interests, but that’s beside the point...)

Very relevant to my interests too :-)

I'm hoping, if I can get a place, to sail from Cape Horn to Cape of Good Hope early next year. I'll be taking a close interest in the navigation, as that's also a big interest of mine, and I'm sure the time and distance will match a spherical Earth rather than a flat one... :-D

[KaiYeves]

Very relevant to my interests too :-)

I'm hoping, if I can get a place, to sail from Cape Horn to Cape of Good Hope early next year. I'll be taking a close interest in the navigation, as that's also a big interest of mine, and I'm sure the time and distance will match a spherical Earth rather than a flat one... :-D

Wow, that’s some serious stuff! Good luck!